CONSIDERATIONS TO KNOW ABOUT UNDERWATER NUCLEAR TEST 'UMBRELLA' (1958)

With test moratoriums to the horizon, American weapons labs rushed out several new layouts. A tough deadline for testing was established at midnight (0000 hrs), 31 October 1958, as negotiations were set to start that day, along with the plan demonstrates it, with 29 tests executed in Oct, 4 of them on the last day. A single other test was cancelled